Simple flat commenting of resources (content, methods and tools)

Description

In the end of each resource page (content, methods, resources) there should be very simple flat anonymous commenting feature. I think people should have extremely easy way to comment, propose or fix things in the resources, without having a user name / password to LeMill.

The comments should be editable / removable by the registered users. Some way to protect the site from spam should be also implemented.

Change History

My experience is that teachers who haven't published their stuff online are a little bit afraid to publish their learning resources. They are not sure that their content is good enough for other teachers. If they get negative anonymous feedback they might be turned away from LeMill.

On the other hand we need a place where to discuss way to improve a certain resource (something like talk page in Wikipedia). Comments under the resource would be easier to notice for teachers than separate talk page. I think that only logged in users should be able to post comments.

For anonymous (and logged in) users we could have a simple portlet for voting, something like voting for reviews in Amazon:

Did you find that content useful?
(Yes) or (No)

(same question for method, tool, collection)

After voting we could display a portlet with message:

13 people have found this content useful.

This way people can get positive feedback. Of course the system can save also negative feedback, but it will not be displayed for users. We can use that feedback as one component in our sorting algorithm.